Powder dispensing applicator

ABSTRACT

Provided is an applicator for the dispensing of a powder such as a pharmaceutical powder, on a target location. Also, provided are methods of applying a powder on a surface using the applicator.

TECHNOLOGICAL FIELD

The presently disclosed subject matter relates to an applicator for thedispensing of a powder such as a pharmaceutical powder, on a targetlocation.

BACKGROUND

Examples of applicators of the kind to which the presently disclosedsubject matter refers, are disclosed in U.S. Pat. No. 9,205,240, WO92/06727, WO 2013/122040, US 2016/0074602 A1 and US 2016/0375202 A1.

U.S. Pat. No. 9,205,240 discloses a device for the topical dispensing ofa powder, which uses a gas flow generator to cause gas to flow throughthe device and to entrain powder from a powder receptacle, while anagitator is used to mechanically agitate the powder receptacle tofacilitate the release of powder from the powder receptacle.

WO 92/06727 discloses a disposable dispenser for a powder, in which themechanism for powder release requires the penetration of membranes,which close two ends of a tubular powder magazine.

WO 2013/122040 A1 discloses a powder injection device, which injectspressurized gas, along with powder contained in a hopper, out of anexhaust pipe.

US 2016/0074602 A1 discloses a delivery device that provides co-deliveryof a liquid medicament and a powder medicament onto a tissue or wound.

US 2016/0375202 A1 discloses a device for the expression of a hemostaticpowder having an elongated reservoir with a manual air pump, such as abellows, at a proximal end and an expression port at a distal end.

Acknowledgement of the above references herein is not to be inferred asmeaning that these are in any way relevant to the patentability of thepresently disclosed subject matter.

GENERAL DESCRIPTION

In accordance with one aspect of the presently disclosed subject matter,there is provided a powder dispensing applicator comprising:

a container having an inlet opening and an outlet opening spaced fromeach other along a longitudinal axis L of the applicator by a cavityconfigured to contain a powder therein at least in the vicinity of theoutlet opening when the outlet opening is in a closed state and allowsat least a part of the powder to be expelled therefrom when the outletopening is in an open state;

an actuator comprising a deformable actuation element configured tocontain a gas therein and to be brought from its initial state, in whichit has a maximal operational volume, into a final state in which it hasa minimal operational volume, via an intermediate state, in which it hasan intermediate operational volume smaller than the maximal volume, forbuilding up pressure in the applicator when the outlet opening is in itsclosed state; and further configured for being brought from its finalstate into its initial state by drawing ambient gas thereto from anexterior of the applicator after the built-up pressure is released; and

a plug configured to obstruct the outlet opening for keeping it in theclosed state until the plug is operated by the actuator to bring theoutlet opening into the open state when the actuation element is broughtfrom the intermediate state into the final state, to create a flow ofthe gas generated due to a pressure differential between that within theapplicator and that at its exterior, for propelling therewith at least aportion of the powder out of the outlet opening in a pressurized burst.

The above structure of the applicator, and particularly, the fact that apressure differential is built up within the applicator immediatelyprior to the outlet opening being brought into its open state, enablesit to dispense powder in a pressurized burst without the use of anexternal pressurized gas source. Moreover, due to the above structure ofthe applicator, it can be configured so that, at each pressurized burstcreated thereby only a part of the powder (a single dose) is propelledfrom the container of the applicator, allowing thereby repeated dosagepowder application. However, if desired, the applicator can be designedto dispense all the powder at once.

In some embodiments, the plug can be configured to be moved between anobstructing position, in which the outlet opening is closed thereby, andan unobstructing position, in which the plug is moved away from theoutlet opening and is thus open.

In some embodiments, the outlet opening can be in the form of an axiallyextending passage having passage inner walls, in which the plug isdisposed between the passage inner walls when in its obstructingposition, and from which the plug is moved away from the passage innerwalls into its unobstructing position.

In some embodiments, the actuator can be configured to selectively exerton the plug an opening force directed along the axis L to move the plugfrom the obstructing position into the unobstructing position; and aclosing force directed along the axis to bring the plug into theobstructing position from the unobstructing position, when the openingforce is terminated, and maintain it in this position until the openingforce is exerted, one of the opening and closing forces being directedtowards the cavity and the other one of these forces being directed awayfrom cavity.

In some embodiments, the actuator can comprise at least one forcetransmitting element manipulatable, at least indirectly, by thedeformable gas-containing actuation element, so as to exert the openingforce to the plug when the deformable gas-containing actuation elementis brought from the intermediate state into the final state.

In some embodiments, the actuator can comprise at least one forceexerting element configured to manipulate, at least indirectly, theforce transmitting element so as to exert the closing force on the plugwhen the deformable gas-containing actuation element is returned fromits final state to its initial state. The force exerting element canhave any appropriate structure. For example, it can be in the form of aspring, which is brought into a compressed state when the forcetransmitting element exerts the opening force on the plug to bring itinto the unobstructing position, and an extended state, in which theforce transmitting element exerts on the plug the closing force, tobring the plug into the obstructing position. Optionally, the spring canbe configured to be maintained in its extended state until thedeformable gas-containing actuation element is brought into theintermediate state from its initial state, and to be compressed at leastindirectly by the deformable gas-containing actuation element when it isbrought from the intermediate state into the final state.

In some embodiments, the deformable gas-containing actuation element canhave a maximal amount of gas therein in the initial state when it hasthe maximal operational volume, and a minimal amount of gas therein inthe final state when it has the minimal operational volume, and it canbe sealingly connected to the container so as to introduce the gas intothe cavity via the inlet opening along the axis L, when being broughtfrom the initial state into the intermediate state, for building uppressure within the cavity when the outlet opening is in its closedstate.

In some embodiments, the gas-containing actuation element can beconfigured to draw ambient air inside it at least partially via theoutlet opening and the cavity, to increase its volume from the minimaloperational volume to the maximal operational volume when it is returnedfrom its final state to its initial state.

In some embodiments, the force exerting element can be configured sothat the duration of time necessary for the force exerting element tocause the plug to be brought into its obstructing position from itsunobstructing position is selected so as to allow the gas-containingactuation element to increase its volume from the minimal operationalvolume to at least the intermediate volume before the plug obstructs theoutlet opening.

In some embodiments, the applicator can comprise at least one internalelement disposed within the cavity of the container and configured tointroduce turbulence into the flow of gas when propelling at least aportion of the powder. In some embodiments, the internal element cancomprise at least one rib. Optionally, the rib can protrude inwardlyfrom an inner wall of the container defining the cavity.

In some embodiments, the applicator can comprise a gas-permeable filterhaving a first side facing the inlet opening and a second side facingthe outlet opening, and disposed in the cavity so as to create betweenthe second side of the filter and the outlet opening a chamber for thepowder, the filter being configured to form a barrier to the powder forpreventing the powder from moving through the filter towards the inletopening.

In accordance with another aspect of the presently disclosed subjectmatter, there is provided a powder dispensing applicator comprising acontainer having an inlet opening and an outlet opening spaced from eachother by a cavity configured to contain a powder therein at least in thevicinity of the outlet opening; an actuator comprising a deformablegas-containing actuation element configured for building up pressure inthe applicator when the outlet opening is in its closed state; and atleast one internal element in the cavity configured to introduceturbulence into the gas when propelling at least a portion of the powderout of the outlet opening in a pressurized burst when the outlet openingis in the open state, by a flow of the gas generated due to a pressuredifferential between that within the applicator and that at itsexterior.

The applicator according to this aspect of the presently disclosedsubject matter can have any one or more of the features of theapplicator according to the first aspect of the presently disclosedsubject matter.

In accordance with a still further aspect of the presently disclosedsubject matter, there is provided a method of applying a powder on asurface using a powder dispensing applicator comprising a containerhaving an inlet opening and an outlet opening spaced from each other bya cavity configured to contain a powder therein, the method comprising:

pressurizing a gas contained in the applicator while maintaining theoutlet opening closed;

subsequently opening the outlet opening to create a flow of the gasgenerated due to a pressure differential between that within theapplicator and at its exterior, for propelling therewith at least aportion of the powder out of the outlet opening in a pressurized burst;and

allowing drawing ambient gas into the applicator from its exterior afterthe built-up pressure is released.

The above method can enable the applicator used therein to dispensepowder in a pressurized burst without the use of an external pressurizedgas source. Moreover, the method can be configured so that, at eachpressurized burst created therein only a part of the powder (a singledose) is propelled from the container of the applicator, allowingthereby repeated dosage powder application. However, if desired, themethod can be used to dispense all the powder at once.

The applicator used in the method according to this aspect of thepresently disclosed subject matter can be constituted by the applicatoraccording to the first and/or second aspect of the presently disclosedsubject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosedherein and to exemplify how it may be carried out in practice,embodiments will now be described, by way of non-limiting examples only,with reference to the accompanying drawings, in which:

FIGS. 1A, 1B and 1C are schematic perspective illustrations of a powderdispensing applicator, in accordance with an example of the presentlydisclosed subject matter, with its deformable gas-containing actuationelement in an initial, intermediate and final state, respectively;

FIGS. 2A and 2B are schematic perspective illustrations of a powderdispensing applicator, in accordance with a further example of thepresently disclosed subject matter, with its outlet opening in a closedand open state, respectively;

FIG. 3A is a schematic perspective illustration of a powder dispensingapplicator, in accordance with a still further example of the presentlydisclosed subject matter, having internal ribs;

FIG. 3B is a top view of a container of the applicator shown in FIG. 3A;

FIG. 4 is a schematic perspective illustration of a powder dispensingapplicator, in accordance with a still further example of the presentlydisclosed subject matter, having a filter; and

FIG. 5 is a schematic perspective illustration of a powder dispensingapplicator, in accordance with a still further example of the presentlydisclosed subject matter, having all of the elements of the exemplaryapplicators shown in FIGS. 1A-1C, 2A-B, 3A and 4, with suitablemodifications, where required, as well as a disposable applicator tip.

It is noted that whether or not structural support and/or fasteningelements are shown in the drawings, they should be assumed to be presentand to be in the form of any suitable means known in the art.

DETAILED DESCRIPTION OF EMBODIMENTS

FIGS. 1A, 1B and 1C show a powder dispensing applicator 10 according toone embodiment of the presently disclosed subject matter. The powdermaterial may be in the form of, or comprise, particulate material suchas granules, microcapsules, aggregates, fibers or a mixture thereof. Thepowder can be composed of a single type of powder or particulatematerial, or a mix of powders and/or particulate material such as ORCpowder, agglomerated ORC powder, gelatin particles, starch particles,gums, sugars, chitosan particles, fibrinogen particles, and thrombinparticles.

The powder dispensing applicator 10 comprises a container 20 having aninlet end 21 with an inlet opening 22 and an outlet end 23 with anoutlet opening 24 spaced from each other along a longitudinal axis L ofthe applicator 10, by a cavity 30 configured to contain a powder thereinat least in the vicinity of the outlet end 23, a plug 50 configured toobstruct the outlet opening 24 for keeping it in a substantially closedstate, and an actuator 40 configured to manipulate the plug 50 to bringthe outlet opening 24 into its substantially open state.

In the embodiment of the applicator 10 illustrated in FIGS. 1A, 1B, and1C, the actuator 40 comprises a deformable gas-containing actuationelement 42, sealingly connected to the container 20 at the inlet end 21thereof so that its gas containing interior is in fluid communicationwith the cavity 30 at least when the outlet opening 24 is to be broughtfrom its closed state into its open state, allowing the actuationelement 42, when operated manually or automatically, to introduce gascontained in element 42 into the cavity 30 through the inlet opening 22for building up a desired pressure in the cavity 30 when the outletopening 24 is in its closed state. The actuation element 42 thus has aninitial state, in which it has a maximal amount of gas therein, and isoperable to be brought into an intermediate state, in which pressure isbuilt up in the cavity 30 when a part of the gas from the actuationelement 42 is introduced into the cavity 30 via the inlet opening 22.

In addition to the ability of the actuation element 42 to be broughtfrom its initial state into its intermediate state as described above,the actuation element 42 is configured to manipulate the plug 50, afterthe desired pressure has been built up in the cavity 30. Moreparticularly, the actuation element 42 can be configured for beingbrought, manually or automatically, from the intermediate state, into afinal state so that, while undergoing this change of state, it isconfigured to exert on the plug 50 an opening force causing it to moveaway from the cavity 30 and the outlet opening 24 in the direction R1,as indicated in FIG. 1C.

In some embodiment, the plug 50 is configured to be moved between anobstructing position, in which the outlet opening 24 is closed thereby,and an unobstructing position, in which the plug 50 is disposed furtherfrom the cavity 30 (or from the outlet opening 24) than in theobstructing position and in which the outlet opening 24 is thus open.

In order to exert the opening force on plug 50, the actuator 40 canfurther comprise a force transmitting element, e.g. such as element 46,shown in FIGS. 1A, 1B, and 1C, manipulatable at least indirectly e.g. bythe actuation element 42, so as to exert the opening force on the plug50 when the actuation element 42 is brought from the intermediate stateinto the final state, thereby bringing the outlet opening 24 into itsopen state.

In the applicator 10 shown in FIG. 1A, the actuation element 42 is inthe form of a bellows 49 having a closed proximal end 43′, an opendistal end 43″ defining the inlet opening 22 at its area close to theaxis L and a bellows interior void 39 therebetween. The bellows 49 issealingly fixed to the container 20 at its area radially spaced from theinlet opening 22. The force transmitting element of the applicator 10shown in FIG. 1A is in the form of a rod 46 passing through the inletopening 22 and the outlet opening 24 and having its proximal end 48within the interior void 39 of the bellows 49 and its distal end withthe plug 50 disposed distally with respect to the outlet opening 24.FIG. 1A shows the bellows 49 and the rod 46 in their initial states, inwhich the bellows 49 has a maximal volume and/or amount of gas, such asair, within its interior void 39, and a maximal distance Bmax betweenits proximal end 43′ and the inlet opening 22, and the rod 46 has itsproximal end 48 at a distance R from the inlet opening 22, and the plug50 located at the distal end of the rod disposed at a location abuttingand obstructing the outlet opening 24, defining the closed state of theoutlet opening 24.

It will be appreciated that the rod 46 and the plug 50 shown in FIGS.1A, 1B, and 1C can be assembled together from separate units, orconstructed as a monolithic unit.

FIG. 1B shows the applicator 10 with the bellows 49 in its intermediatestate, and with the plug 50 staying in its obstructing position definingthe closed state of the outlet opening 24. To bring the bellows 49 intothis state, it has to be axially pressed at its proximal end 43′thereof, e.g. manually by a thumb (not shown) of a user, and compressedso that its proximal end 43′ moves to a distance Bint from the inletopening 22, causing a part of the gas to flow from the interior void 39of the bellows into the cavity 30 via the inlet opening 22. Since theplug 50 maintains its obstructing position, closing off outlet opening24 of cavity 30, and inlet end 21 of cavity 30 is closed off by thesealed connection with bellows 49, which is itself closed, theintroduction of gas from the interior void 39 of the bellows 49 into thecavity 30 causes a pressure within the cavity to be built up. Thedistance Bint is selected so as to be not shorter than the distance R tomake sure that the proximal end 43′ of the bellows 49 does not exert anyforce on the proximal end 48 of the rod 46, and does not cause the rod46 to move the plug 50 away from the outlet opening 24 until thepressure built up in the cavity 30 reaches a predetermined value.

It will be appreciated that the amount of pressure built up in thecavity 30 as described above can be a function of one or more of thephysical and configurational parameters of the applicator 10, e.g., theratio between Bmax and R, the ratio between the volume of the cavity 30and the interior void 39 of the actuation element 42, etc. For example,in the applicator 10, Bmax could be between 2.3 to 2.7 times the lengthof R, and the volume of cavity 30 could be between 1 and 1.3 times thevolume of the interior void 39 of the actuation element 42.

In another example, the length of element 46 can be decreased orincreased so as to change the dimension R, the extent to which theelement 46 extends into the interior void 39 of the actuation element42, in order to control the pressure built up in cavity 30 prior to itsrelease.

It will further be appreciated that pressure can be built up in thecavity 30 as described above, even while the connection betweenactuation element 42 and container 20 is not completely sealed to gas.

It will be appreciated that in FIGS. 1A-1C and the description providedabove, the initial, intermediate and final states of the actuationelement 42 are presented as distinctive states in order to describe inclear detail how the applicator 10 works. However, it is to beunderstood that in ordinary operation of the actuation element 42 of theapplicator 10, its above states can be taken successively andcontinuously, i.e. without any intervals therebetween, by pressing theactuator in one movement which can be as rapid as desired.

It will further be appreciated that in the applicator of the presentlydisclosed subject matter, alternative means of gas compression, such asa shape memory elastic bulb, or a piston within a cylinder, can be usedin place of a bellows, such as that illustrated in FIG. 1 .

Continued axial pressing (distally) on the proximal end 43′ of thebellows 49 causes the bellows, as shown in FIG. 1C, to push distally theproximal end 48 of the rod 46 and to move therewith towards the inletopening 22, whereby the bellows 49 reaches its final state characterizedby the minimal spacing Bmin of the proximal end 43′ of the bellows 42from the inlet opening 22, and by the minimal amount of gas in theinterior void 39 of the bellows 49. It is noted that a small spaceappears in FIG. 1C between proximal end 43′ of the bellows 49 andproximal end 48 of the rod 46 for the sake of clarity of the parts inthe illustration only, and that as described above, proximal ends 43′and 48 of the bellows 49 and the rod 46 respectively, should beconsidered to be in contact with one another when the bellows is in itsfinal state.

When the rod 46 is pushed distally by the proximal end 43′ of thebellows 49, the rod exerts on the plug 50 the opening force, directedalong longitudinal axis L away from the cavity 30, thereby moving plug50 away from the outlet opening 24 into its unobstructing position, thusbringing the outlet opening 24 into the open state.

The fact that prior to opening the outlet opening 24, the pressure hasbeen built up in the cavity 30 to a pressure P1, leads to the creationof a pressure differential between that within the cavity 30 and theoutside atmosphere (atm) (i.e., P1>P_(atm)), such that when the outletopening 24 is opened, a pressurized gas flow is generated out of theoutlet opening 24. When the cavity 30 contains a powder therein at leastin the vicinity of the outlet opening 24, this pressurized gas flowcauses at least a portion of the powder, i.e. a powder dose, to bepropelled out of the outlet opening in a pressurized burst.

Thus, during the movement of plug 50 away from its obstructing positioninto its unobstructing position, the powder contained in the applicatoris dispensed.

In one example of an applicator 10 having an initial bellows volume of10 ml in the initial state, and a final bellows volume of 5 ml in thefinal state, in accordance with the presently disclosed subject matter,the pressure in cavity 30 could reach a pressure of between 1.1 and 3atm such as 1.25, 1.45 atm just prior to opening of outlet opening 24.

It will be appreciated that this pressure is built up inside theapplicator provided in accordance with the presently disclosed subjectmatter without an external pressurized gas source.

It will be appreciated that one advantage of the pressurized burst ofpowder released from applicator 10 in accordance with the presentlydisclosed subject matter is the precise application of the powder doseon a target location, in an accurate and consistent distribution, sincethe powder is released from the outlet opening 24 in a pressurized burstof spray which creates a focused aerosol and powder spots on the targetlocation.

It will further be appreciated that an additional advantage of thepressurized burst of powder released from applicator 10 in accordancewith the presently disclosed subject matter is that it allows the powderburst to be directed in any possible direction including the horizontaldirection as well as the vertical upward direction, i.e. against theforce of gravity, since the powder disposed in the cavity at least inthe vicinity of the outlet opening is propelled as a spray from outletopening 24 with kinetic energy and has its own momentum, allowing it totravel some distance before being counteracted by gravity. It willfurther be appreciated that the powder can be applied even while theorientation of the applicator itself its changing, from the vertical tothe horizontal, upwards, downwards and every angle in between.

The freedom to spray powder without restrictions enables the applicatorto be used more intuitively by a user. Furthermore, access to otherwisedifficult to reach locations is allowed.

It will further be appreciated that the applicator provided inaccordance with the presently disclosed subject matter can be configuredsuch that the distance which the plug 50 is moved away from the outletopening 24 can be increased such as to effectively increase the area inthe vicinity of outlet opening 24 which is unobstructed by plug 50,thereby reducing the velocity of the gas and powder flow exiting theapplicator.

In another embodiment, the actuator 40 can further comprise a forceexerting element configured to manipulate at least indirectly the forcetransmitting element 46 so as exert on the plug 50, a closing force. Theclosing force is directed along the longitudinal axis L towards cavity30 and brings the plug 50 into the obstructing position from theunobstructing position, when the opening force is terminated, and itmaintains the plug 50 in the obstructing position until the openingforce is exerted.

One example of an applicator having such a force exerting element isshown in FIGS. 2A and 2B and is designated as 110. The applicator 110has the same components, and is operated in the same manner as theapplicator 10 shown in FIGS. 1A, 1B and 1C, and it differs from theapplicator 10 in that it has the above mentioned force exerting element,which in the applicator 110 is in the form of a spring, designated 44 inFIGS. 2A and 2B. The spring 44 is configured to be brought into acompressed state when the force transmitting element 46 exerts theopening force on the plug 50 to bring it into the unobstructing position(FIG. 2B), and an extended state, in which the force transmittingelement 46 exerts on the plug 50 the closing force, to bring the plug 50into the obstructing position (FIG. 2A).

The spring is furthermore configured to be maintained in its partiallyextended or extended state until the deformable gas-containing actuationelement 42 is brought into the intermediate state from its initialstate, and to be compressed at least indirectly by the deformablegas-containing actuation element 42 when it is brought from theintermediate state into the final state.

In the applicator 110, in order for spring 44 to be held within thecontainer 20 so as to be compressible when the bellows 42 exertsdirectly or indirectly on the plug 50 the opening force, there isprovided in the cavity 30, a proximal spring seat 47 held by the rod 46and movable therewith by the actuation element 42, and distal springseat 62 fixed to the inner surface of the container 20. The proximalspring seat 47 can constitute a unitary body with the rod 46 or can beassembled therewith at a location disposed distally to its proximal end48 but closer to this extremity than to the distal spring seat 62, alonglongitudinal axis L of applicator 110. The distal spring seat 62 can beformed as a unitary body with the container 20 or can be assembledtherewith, and it can have a central passage 63 configured to surroundthe rod 46 allowing its free movement therealong, when moving the plug50 between its positions corresponding to the open and closed states ofthe outlet opening 24.

The spring 44 is brought into its compressed state by the actuationelement 42, when the actuation element 42 applies to the rod 46 with theplug 50, the distally pushing, opening force, shown in FIG. 2A as forceF1, thereby moving distally the proximal spring seat 47. This seat 47then exerts on the spring 44, which abuts the fixed distal spring seat62, a force F_(s)=−kΔx, where k is the spring constant and Δx is thedistance through which the spring is compressed. When the opening,distally pushing force is terminated, the spring 44 tends to expand,thereby exerting on the rod 46 with the plug 50, via the proximal springseat 47, the closing, proximally pulling force, shown in FIG. 2A asforce F2, causing the plug 50 to return to obstruct the outlet opening24 and keep it in its closed state as long as no opening, distallypushing force is exerted on the plug 50. This closed state characterizesthe default state of the applicator 110, which is maintained at alltimes except when the actuation element 42 is operated to be broughtfrom its intermediate into its final state by the user's pressingthereon until the opening, distally pushing force is exerted on the plug50, whereby the unintentional powder release out of the applicator dueto gravity or occasional movement is prevented.

An additional advantage of the applicator 110 being in the closedposition by default, is that the applicator is thus always in aready-to-use position. The applicator 110 can thus be immediatelyoperated to express powder, without any requirement for the user tofirst activate it, e.g., to change its mode from ‘off’ to ‘on’. Thisincreases the user-friendliness of the applicator, making it moreintuitive to use, and thereby helping to prevent confusion during usethat can hinder smooth operation of the applicator.

It will further be appreciated that since the applicator returns to aready-to-use position after each use, repeated dosing is enabled. In aconfiguration of applicator 110 in which only a portion of the powder incavity 30 is used in each dose, the applicator can be used repeatedlyuntil the powder in cavity 30 is all used up, thus maximizing thepercentage of powder provided in the applicator which is ultimatelyused, and minimizing the wastage of powder.

It will be appreciated still further, that pressure is built up incavity 30 for each use of the applicator, so that each sequential dosein a series of doses provides all the benefits provided in the initialdose without any reduction in efficacy, i.e., powder application isachieved via a pressurized burst in the manner described above in eachand every application. In the example of applicator 110, after the userdesists from pressing on proximal end 43′ of the bellows 42, and thespring 44 exerts the closing force as described above to move the plug50 from the unobstructing position into the obstructing position, thedeformable gas-containing actuation element 42 draws ambient air intoits interior void 39, thus returning it from its final state to itsinitial state, in which state it is ready again for operation to deliverthe next pressurized dose of powder.

When the deformable gas-containing actuation element 42 is released, itreturns to its original volume, resulting in a decrease of pressure inthe interior void 39, a flow of ambient air into the interior void 39and pressure equilibration. The flow of ambient air into the interiorvoid 39, can occur via the outlet opening 24 until it becomes closedand/or via interstitial spaces between components of the applicator,which can be not completely sealed to gas, as mentioned previously withrespect to the connection between the actuator 42 and the container 20.

In one embodiment, the deformable gas-containing actuation element 42can be configured with an opening, for example, in the closed proximalend 43′ of bellows 49. During operation, this opening can be sealed bythe thumb of the user during the pressing of the bellows 49 when it iscompressed from its initial state to its final state. The release of thethumb from the bellows then allows ambient air to flow into the interiorvoid 39 due to the pressure differential formed as plug 50 moves back toits obstructing position at outlet opening 24 and bellows 49 returnsfrom its from its final state to its initial state.

It is also clarified that in general the extended state of the spring 44can be actually a partially compressed state of the spring, with respectto its physical parameters, as it is configured in accordance with thepresently disclosed subject matter to exert the closing force in thisstate, which is provided by the potential energy of its partiallycompressed status as explained above, however, this partially compressedstate is an extended state with respect to the relatively morecompressed state of spring 44 shown in FIG. 2B.

It is also clarified that in general the compressed state of the spring44 can be actually a partially extended state of the spring, withrespect to its physical parameters, as it is configured in accordancewith the presently disclosed subject matter to be compressed to someextent by the opening force exerted by the user which moves the plug 50into its unobstructing position via the rod 46 which passes through thespring 44, however, this partially extended state is a compressed statewith respect to the relatively more extended state of spring 44 shown inFIG. 2A.

Any of the applicators 10 and 110 described above, as well as any otherapplicator according to the presently disclosed subject matter, whichhas a cavity similar to the cavity 30, can comprise at least oneinternal element disposed within the cavity 30, configured to introduceturbulence into the flow of gas when propelling at least a portion ofthe powder out of the outlet opening. Such turbulence can beadvantageous at least for reducing the amount of residual powder thatcan be left in the cavity 30 after the use of the applicator. Theturbulence can further be advantageous for achieving a more uniformsuspension of the powder in the gas.

The internal element can be at least one rib, which can have anyappropriate shape such as, e.g., a blade-like shape. An example of anapplicator which has the above internal element, and in addition has thesame features as the applicator 10, is shown in FIGS. 3A and 3B, wherethe applicator is designated as 210, an inner wall of the container 20is designated as 28 and the blade-like ribs protruding from the innerwall 28 into the cavity 30, are designated as 60.

When a laminar flow of gas entering cavity 30 from the actuation element42 impinges upon the ribs 60, the direction of the flow of gas isshifted toward the inner wall 28 while moving distally. This can have asweeping effect on particles of powder positioned close to, or clingingto the inner wall 28, such that these particles are propelled out ofoutlet opening 24, rather than remaining in the applicator 10 and notbeing used. Thus, the greatest possible percentage of the total volumeof the powder in the applicator is more likely to be used, i.e.,propelled through outlet opening 24 during the operation of applicator210, rather than remaining inside the cavity 30 and being wasted. In theevent that the total volume of the powder in the applicator 10 is asingle dose, this can prevent the application of an insufficient orinaccurate dose.

It will be appreciated that the rib 60 can be of any shape and any sizesuch that it creates turbulence in cavity 30. For example, the rib 60can have a radial extension of between not less than 0.25R and notgreater 0.75R, where R is an average distance between the inner wall 28and the longitudinal axis L. An exemplary axial extension of the rib 60could be not less than 0.5 H, wherein H is an axial extension of cavity30.

It will further be appreciated that, in order to further optimize themix of the gas and the powder in the cavity 30 so as to achieve maximaldelivery of powder out of the applicator, the cavity 30 can be filledwith powder so that the powder occupies up to 85-90% of the total freevolume of the cavity 30, so as to leave a void space in the cavity freefrom powder.

Any of the applicators 10, 110 and 210 described above, or any othersimilar applicator according to the presently disclosed subject matter,can comprise a gas-permeable filter fitted within the cavity 30 adjacentto the inlet opening 22 so as to prevent the powder from moving from thecavity 30 into the actuation element 42 through the inlet opening 22,but to allow gas entering the cavity 30 from the actuation element 42through the inlet opening 22, to pass through the filter (and onlythrough the filter) towards the outlet end 23 of the container. Thefilter can have a first side facing the inlet opening 22 and a secondside facing the outlet end 23 of the container 20 and can be disposed soas to create a chamber for the powder between the second side of thefilter and the outlet end 23 of the container. An example of anapplicator which has the above filter and in addition has the samefeatures as the applicator 10, is shown in FIG. 4 , where the applicatoris designated as 310, the filter is designated as 70, its first side isdesignated as 72, its second side is designated as 74 and the chamber isdesignated as 32.

It will be appreciated that the filter provided in the presentlydisclosed subject matter can be affixed by any suitable means to theinterior of the container 20, e.g. to the inner wall 28 of the cavity30, and thus not rest directly on the powder contained in theapplicator, and therefore not apply any force on the powder.Aggregation, agglomeration and caking of the powder is thus prevented.

In all of the above described applicators, the outlet end 23 of thecontainer 20 is shown to have an axially extending outlet port 41 havingthe outlet opening 24 at its proximal end and a plug passage 55extending distally from the outlet opening 24 so as to allow the plug 50to move therealong from its proximal position, in which it abuts andobstructs the outlet opening 24, into its distal position, in which itdoes not obstruct it, being distally spaced therefrom along the passage55. The plug 50 is shown to have such a cross-sectional shape as to belarger than the outlet opening 24 in at least one cross-sectionaldimension in order to prevent axial movement of the plug 50 in theproximal direction, when the outlet opening 24 is in its closed state.The passage 55 can have such cross-sectional shape along its lengthspaced from the outlet opening 24 as to allow the plug to move freelytherealong away and towards the outlet opening 24 when bringing it intoits respective open and closed states.

For example, plug passage 55 can have passage internal walls 56 such asshown in FIG. 1A. Plug 50 can be disposed between the passage innerwalls 56 when in its obstructing position, and it can be moved away fromthe passage inner walls 56 when it is moved into its unobstructingposition.

As further shown in FIG. 1A, the plug 50 has a maximal cross-sectionaldimension Dplug, the outlet opening 24 has a correspondingcross-sectional dimension d, which is smaller than Dplug, and thepassage 55 has a corresponding cross-sectional dimension Dpass, which isgreater than Dplug and which varies along the axis L. In all theapplicators described above, the cross-sectional shape of the plug 50,the outlet opening 24 and the passage 55 is circular, and the aboveindicated dimensions are their corresponding diameters. However, in theabove applicators as well as in any other applicators according to thepresently disclosed subject matter, any one of the plug, the passage 55and the outlet opening can have any other irregular or regularcross-sectional shape such as, e.g. oval or polygonal, in which case theabove dimensions will be the diameters of circles inscribed in thatshape.

In any of the above described applicators or any other similarapplicator according to the presently disclosed subject matter, in someembodiments, the plug 50 can be configured to obstruct only partiallythe outlet opening 24 when bringing it into the closed state so as toprevent the powder from exiting the outlet opening 24, while allowingsome amount of gas to pass through the outlet opening 24. In this case,an extent of the partial obstruction of the outlet opening 24 by theplug 50 should be such as to still allow the pressure differential to begenerated as described above, to propel the pressurized burst of powderout of the outlet opening 24. In any of the above described applicatorsor any other similar applicator according to the presently disclosedsubject matter, in some embodiments, the outlet opening 24 is “closed”for powder but not completely closed for gas. In such embodiment,although the plug is not completely air tight, a pressure differentialcan be generated.

An applicator according to the presently disclosed subject matter cancomprise all or only a part of the features of the applicators 10, 110,210 and 310 described above. An applicator 410 comprising all of thesefeatures is shown in FIG. 5 . In the applicator 410 shown in FIG. 5 ,distal spring seat 62 has been modified to include filter-holdingappendages (not seen).

An applicator according to the presently disclosed subject matter cancomprise additional features not disclosed herein.

In any applicator according to the presently disclosed subject matter anapplicator tip, such as applicator tip 80 shown in FIG. 5 , can be used.The applicator tip can be connected to a hub which is configured to besnap-fitted onto the container 20 of applicator 10 at its distal end,near outlet opening 24, allowing the applicator tip 80 to be exchangedas required, e.g. for exchanging a short applicator tip with a long onein accordance with the application requirements. For example, it can bedesirable to use a tip with a long length for minimally invasiveprocedures.

It will be appreciated that applicator tips with long lengths can beadvantageously used with applicator 10, in that robust powderapplication can still be provided even when the powder is forced totravel the full length of a long applicator tip before being expelledonto the target location, due to the kinetic energy imparted to thepowder spray in the pressurized burst from the applicator provided inaccordance with the presently disclosed subject matter.

The applicator tip 80 can be made of material such as polymer, metal ora combination of the two, and can be rigid, flexible, semi-flexible, orhave shape memory. The bellows 49 can be made out of shape memorymaterial such as plastic resin.

Container 20 can have protrusions to facilitate a good grip of theapplicator with two fingers, while a third finger is used to press theactuation element 42.

In one embodiment, the applicator of this invention can contain powderto be used in a surgical scenario.

In one embodiment, the applicator can be disassembled and filled withpowder by an end user.

The applicator can be comprised of material stable to gamma or eBeamirradiation.

It will be appreciated that the applicator of the presently disclosedsubject matter can have a design or structure which is different fromthe examples shown in the figures.

For example, the applicator can be constructed with elastic materialtaking the place of the spring 44.

In another example, the applicator can be constructed such that the plug50 is pulled into cavity 30 rather than pushed out of cavity 30 in orderto bring outlet opening 24 into the open state.

In another example, the applicator can be constructed such that spring44 is configured to be maintained in a partially compressed orcompressed state, and to expand during the operation of the applicator,such that after application of the powder, the tendency of the spring 44to contract exerts the closing force on the plug 50 to bring outletopening 24 into the closed state.

In another example, the applicator can be constructed such that theopening and closing forces exerted to move the plug at least indirectlycan be exerted by bands, strings, gears or a rod in combination withgears.

In another example, the gas pressure buildup can take place inside theactuation element 42 and not in the cavity 30.

The applicator can be constructed in such a way that in its inoperativestate, there is no fluid communication between the deformablegas-containing actuation element 42 and the cavity 30. For example, aseal can be located at inlet opening 22, such that when the actuationelement 42 is operated, pressure can build up in the actuation element42 rather than in the cavity 30. The seal could then be ruptured, whenpressure in the actuation element 42 reaches a predetermined value, orby mechanical means. At the same time, outlet opening 24 can be opened,either as a result of the buildup of pressure, or by mechanical means,and the powder can be propelled out of the applicator in a pressurizedburst.

In an embodiment of the applicator having a seal as described abovewhich can be ruptured when the applicator is used for the first time,the applicator can be used as a disposable applicator.

It will be appreciated that in one embodiment, the mechanism by whichthe outlet opening 24 is opened is independent of the pressurized gas.In another embodiment, the release of pressurized gas is carried out bya mechanism which is independent of pressurized gas, for example, bymechanical means (such as by pressing proximal end 48 of rod 46.)

1. A powder dispensing applicator, said applicator comprising: acontainer having an inlet opening and an outlet opening spaced from eachother by a cavity configured to contain a powder therein at least in thevicinity of said outlet opening; an actuator comprising a deformablegas-containing actuation element configured for building up pressure insaid applicator when the outlet opening is in its closed state; and atleast one internal element in the cavity configured to introduceturbulence into said gas when propelling at least a portion of saidpowder out of said outlet opening in a pressurized burst when the outletopening is in the open state, by a flow of said gas generated due to apressure differential between that within the applicator and that at itsexterior. 2-17. (canceled)
 18. A method of applying a powder on asurface using a powder dispensing applicator, the method comprising:providing the powder dispensing applicator of claim 1, pressurizing agas contained in the applicator while maintaining the outlet openingclosed; subsequently opening the outlet opening to create a flow of saidgas generated due to a pressure differential between that within theapplicator and that at its exterior, for propelling therewith at least aportion of the powder out of the outlet opening in a pressurized burst;allowing drawing ambient gas into the applicator from its exterior afterthe built-up pressure is released.